For superstitious travelers, that might be tempting fate. But Finnair passengers on AY666 to Helsinki — which has the 3 letter designation HEL — don’t seem too bothered. Friday’s flight is almost full.

“It has been quite a joke among the pilots” said veteran Finnair pilot Juha-Pekka Keidasto, who will fly the Airbus A320 from Copenhagen to Helsinki. “I’m not a superstitious man. It’s only a coincidence for me.”

The daily flight AY666 from Copenhagen to Helsinki falls on Friday the 13th twice in 2013. Friday the 13th is considered bad luck in many countries and the number 666 also has strong negative biblical associations.

Some airlines, like Scandinavian Airlines, take these fears seriously and don’t have a row 13 on board. However, the negative connotations are a relatively new phenomenon for northern Europeans, and Finnair and other regional carriers like Norwegian and Estonian Air keep row 13.

“Less than 100 years ago, the number 13 did not have this sinister meaning; it’s quite recent in the north,” said Ulo Valk, professor of comparative folklore at the University of Tartu in Estonia.

“There are 12 hours, 12 months and in Christianity 12 apostles and this is a divine number. Add one more and it brings in a certain element of chaos,” he said.

But passengers on flight 666 to HEL should have a calm flight over the Baltic at this time of year.

“It’s hopefully smooth skies” says Keidasto. “And if there’s some passenger who is anxious about this 666 our cabin crew is always happy to help them.”